In recent years, the use of portable data terminals to gather, store and/or process information has become increasingly popular. For instance, portable data terminals permit users to conduct word processing, computations, spreadsheet analysis, etc. while traveling or at remote locations. Portable data terminals in the form of personal data assistants (PDAs) allow users to store electronically personal and business information in an organized fashion which may be subsequently downloaded to a main database. Retail stores and warehouses often use portable data terminals in order to keep track of inventory or replenish stock. Hospital personnel use such terminals to keep track of patient information while making rounds. Furthermore, portable data terminals are often used by delivery personal and insurance inspectors to gather data at field locations in order to reduce the amount of paper and to increase efficiency in recording data.
Oftentimes the portable data terminals form part of a wireless network in which data collected within the terminals is communicated to a host computer via a wireless link. For example, the portable data terminals include a radio or optical transceiver for communicating with a host computer via a base station.
Most portable data terminals are constructed generally of the same types of components. For example, portable data terminals typically include a processor for controlling operations and processing information; memory for storing information; a display for displaying information; a keypad for permitting an operator to input data and function commands; etc. Thus, many components utilized in portable data terminals are the same regardless of the particular application (e.g., whether as a word processor, PDA, inventory data collector, patient data collector, etc.). The primary difference is the particular software which is loaded into the data terminal.
Nevertheless, it is typically desirable to utilize a keypad in the portable data terminal which is customized for the particular application. For example, rather than a generic keypad which includes keys with labels which are non-descript descript (e.g., F1, F2, etc.), it is preferable to have a keypad which is specific to the particular application. A portable data terminal used in inventory data collection may have keys designated with labels such as "Stock Item", "Quantity", etc. A portable data terminal for use in a hospital may include keys with labels such as "Patient", "Blood Pressure", etc. Such keys are useful to the operator for providing a clear indication of the function of the respective keys.
Accordingly, there is a need for a portable data terminal which is configurable to accept any of a plurality of different keypads. This allows a keypad having keys labeled with application specific functions to be utilized in an otherwise generic data terminal. Portable data terminals may be assembled by a system integrator using generic components and an application specific keypad. Software may be loaded into the terminal as appropriate.
There have been attempts in the past to provide such a portable data terminal, but these attempts have met with limited success. As an example, U.S. Pat. No. 5,576,981 describes a portable computer with an interchangeable keypad. However, the reference does not clearly describe a means for carrying out such interchangeability in a practical device. U.S. Pat. No. 5,202,817 describes a data capture system with interchangeable keyboard modules, but does not address many of the configuration and environmental issues that can arise in a practical device.
In view of the aforementioned shortcomings associated with conventional devices, there is a strong need in the art for a portable data terminal which may be configured with any of a plurality of different modular keypads in a practical manner. More specifically, there is a strong need for a portable data terminal which is may be easily integrated with a selected modular keypad. Moreover, there is a strong need for such a portable data terminal which includes a modular keypad and is yet rugged enough to handle everyday usage and withstand adverse conditions (e.g., water, dirt, debris, etc.).